This invention relates to suspension seats and to the providing of such seats with fore and aft adjustments and seat belt anchorages. Although the conventional floor mounting for a seat belt is quite satisfactory for an automobile wherein the seat permits a very limited degree of vertical motion, it is not satisfactory for use with a suspension seat which generally provides 4 or more inches of vertical travel. In suspension seats, it has been common to anchor the lap belt to the movable side frame of the seat and then anchor the movable seat frame to the floor with a tether belt which is adjusted to be taut in the extreme upper position of the suspension. An example of such a mounting can be seen in Barecki et al. U.S. Pat. No. 3,493,211. A problem with the last mentioned type of mounting arises when the seat is of the type having a capability of being adjusted in a fore and aft direction. Since a typical adjustment range for such a seat is about 4 inches, it will be readily appreciated that the movable seat frame to floor tether belt must be sufficiently long to accommodate the entire range of vertical seat movement while the seat is in its extreme forward position. When the seat is in any other fore and aft position, the tether belt will be slack in the uppermost position of the seat suspension and therefore incapable of offering any restraint until after the seat has been damaged by being moved upwardly beyond its upper limit.
Means for overcoming the problems of too much slack in the tether belt are described in Hall et al U.S. Pat. No. 3,737,197 and Radke et al. U.S. Pat. No. 3,758,158 wherein the lap belt and tether belt are connected to a support member which is free to move up and down with the seat but which is restrained from moving horizontally at any vertical position of the seat by being connected to a pivot link means which is connected to the floor and to the support member. The support member includes a guide portion which cooperates with a slide member affixed to the movable seat frame to permit the seat and slide member to move horizontally relative to the guide portion so that the seat can be adjusted fore and aft without affecting the amount of slack in the tether belt. The slide member also transmits the vertical motion of the seat frame and suspension to the guide portion which moves up and down generally vertically. U.S. Pat. 3,811,727 discloses a support system similar to that in the aforementioned Hall et al and Radke et al. patents but which eliminates the separate tether belt by anchoring a pivot link for the support member to the vehicle floor behind the seat. In each of the just mentioned three disclosures the seat belt anchorage is separate from the anchorage for the seat, entailing the additional expense of the time and materials necessary for preparing the vehicle and mounting the separate anchorages to it. Furthermore, in the arrangement shown in U.S. Pat. No. 3,811,727, it is important that the separately mounted seat base and pivot links be accurately installed relative to each other and on properly reinforced portions of the vehicle floor to prevent binding and to insure that the lap belt loads will be adequately supported.